A patient with the Ebola virus is expected to arrive at a special “containment unit” at Emory University Hospital in Atlanta “in the next several days,” but the identity of the patient cannot be released, a university news release said Thursday.

The only known Ebola outbreak in the world is in West Africa, so speculation about the patient centers on the two Americans known to have contracted the virus in Liberia: Dr. Kent Brantly, a former JPS Hospital resident, or Nancy Writebol of Charlotte, N.C., a hospital hygenist. Both work for North Carolina-based Samaritan’s Purse, a Christian relief organization.

Brantly and Writebol were in “stable but grave” condition at a Monrovia, Liberia, hospital Thursday morning, according to Samaritan’s Purse.

A Emory University spokeswoman said she could not release the incoming patient’s name because of the federal privacy law covering health information.

In a White House news briefing Thursday, spokesman Josh Earnest said the U.S. was working with the Centers for Disease Control and Prevention, also in Atlanta, to explore Medevac options for humanitarian aid workers in West Africa who have contracted the disease. While U.S. officials would facilitate the effort, Earnest said, private companies would perform the evacuation.

Earnest said the aim of the operation would be to make sure aid workers have access to “modern medical facilities and technology” and “potentially lifesaving aid.” He called the response consistent with past protocols during outbreaks of SARS and drug-resistant tuberculosis.

CDC Director Tom Frieden said Thursday that the decision to evacuate sick aid workers was a “very complicated question,” but said the decision was up to the aid organizations they work for.

“There is the potential that the actual movement of the patient could do more harm than the benefit from more advanced supportive care outside the country,” Frieden told reporters in a conference call. “We would certainly work with them to facilitate whatever option they pursue.”

Emory University Hospital set up the isolation unit in collaboration with the CDC. It is physically separate from other patient areas and “has unique equipment and infrastructure that provide an extraordinarily high level of clinical isolation,” the hospital statement said.

The unit is one of only four in the country. The doctors, nurses and staff are specially trained the the protocols and procedures necessary to care for that type of patient.

Brantly, who contracted the virus while working at the same hospital where he is now being treated, turned down the offer of a dose of an experimental serum and asked that it be given to Writebol, according to a post Thursday on the Samaritan’s Purse website.

“Yesterday, an experimental serum arrived in the country, but there was only enough for one person. Dr. Brantly asked that it be given to Nancy Writebol,” said Franklin Graham, president of Samaritan’s Purse in the website posting at samaritanspurse.org.

“However, Dr. Brantly received a unit of blood from a 14-year-old boy who had survived Ebola because of Dr. Brantly’s care. The young boy and his family wanted to be able to help the doctor that saved his life.”

There is no known cure or vaccine for Ebola hemorrhagic fever, according to the CDC and World Health Organization. Patients are often quarantined and given IV drips to combat dehydration.

Frieden said Thursday that he could not comment on the treatments because he did not have any details about them, but emphasized that he believes an effective treatment for Ebola is at least a year away.

“We are not going to treat or vaccinate our way out of these outbreaks,” Frieden said. “We’re going to use the traditional means that work: identification, isolation, contact tracing … and good, meticulous infection management.”

Samaritan’s Purse and SIM, which together ran the Liberian facility where Brantly and Writebol work, have said they are evacuating all nonessential personnel from the country, and expect the evacuations to be completed this weekend. They emphasized that none of those being evacuated is sick, and that their health will be monitored after they leave the region.

Star-Telegram writers Bill Hanna, Diane Smith and Judy Wiley contributed to this report, which includes material from the Los Angeles Times.